Multimedia communications services based on the Session Initiation Protocol (SIP) will bring a range of new fixed and mobile applications to corporate customers.

But progress could be delayed by interoperability problems in the IP Multimedia Subsystem (IMS) that carriers are currently building into their next-generation network (NGN) infrastructure.

Dr Eric W Burger, chief technology officer of IP communications vendor Cantata, said IMS can provide the means for carriers to deliver new SIP-based applications to firms at any location over any network, and also make the delivery of old applications more economical.

IMS also allows telcos to buy standard components from many different vendors, fostering competition among suppliers that should further reduce carriers’ operational costs.

“The focus of IMS is service development and deployment, not just low-cost data transport. Simple, cheap calling has been played out and operators now need to find interesting services for businesses that they can deliver economically,” said Burger.

Bahaa Moukadam, vice-president of IP telephony at carrier Spirent, added, “The goal five to 10 years from now is for carriers to deliver the same user experience and services over both wired and wireless networks, no matter where the user is, but there are lots of interoperability issues to be worked out first.”

BT is currently constructing its NGN with IMS as a major component. And Carphone Warehouse’s network operating subsidiary, Opal Telecom, announced last month that it will deploy a converged IP network in the UK with IMS functions for consumers and businesses.